In 1996, the IOM identified continuity of care as a core attribute of primary care because it should result in better quality care, disease management, and subsequent health outcomes, especially for older adults with one or more chronic conditions. In 2003 the IOM made continuity of care a primary aim in its comprehensive call for national action to transform health care quality. Continuity of care was also the centerpiece of the ACP's 2006 call for revolutionary reforms to restructure the American health care delivery system. Despite its centrality, no theoretically- driven measure exists for the standard assessment of continuity of care, nor has there been a comprehensive evaluation of the association of continuity of care with subsequent health outcomes. We propose a comprehensive evaluation of the association between our newly developed Medicare claims-based measure of interpersonal continuity of care and subsequent health outcomes. We will conduct this evaluation by linking data from four sources: (1) the 1993 baseline and 1995, 1998, 2000, 2002, and 2004 follow-up interviews with the 7,447 AHEAD subjects; (2) the NDI; (3) county identifiers for the AHEAD subjects; and, (4) Medicare Part A and B claims for calendar years 1989 through 2004. We will evaluate four specific hypotheses: (H1) AHEAD subjects with interpersonal continuity will have higher self-rated health (SRH) levels at baseline, and over time their SRH trajectories will decline more slowly than those without interpersonal continuity; (H2) AHEAD subjects with interpersonal continuity will have difficulty with fewer activities of daily living (ADLs), instrumental ADLs (IADLs), and lower body functions (LBFs) at baseline, and over time their ADL, IADL, and LBF trajectories will increase at a slower rate than those without interpersonal continuity; (H3) AHEAD subjects with interpersonal continuity will be less likely to be hospitalized for ambulatory care sensitive conditions (ACSCs) after baseline, and when hospitalized for ACSCs this will occur later than for those without interpersonal continuity of care; and, (H4) AHEAD subjects with interpersonal continuity will have lower mortality rates and will live longer than those without interpersonal continuity. H1 will be tested using mixed effects models and hierarchical (three levels: time, subject, county) linear modeling. H2 will be tested using a similar approach to H1, but with generalized linear mixed effects models. H3 will be tested using two-level random-effects logistic regression models and Cox-frailty models. H4 will be tested using a similar approach to H3. Extensive sensitivity analyses are proposed, and we have more than 80% power (two-tailed alpha = .05) to detect minimal clinically meaningful changes for all health outcomes under consideration. The role of interpersonal continuity of care is central to proposals from the Institute of Medicine (IOM, 2003) and the American College of Physicians (ACP, 2006) for restructuring the American health care delivery system. However, until now no theoretically-driven measure has existed for the standard assessment of interpersonal continuity of care, nor has there been a comprehensive evaluation of the association of interpersonal continuity of care with subsequent health outcomes. In this R21 application, we propose to conduct a comprehensive evaluation of the association between continuity of care and subsequent health outcomes using our newly developed, Medicare claims-based measure of interpersonal continuity of care. [unreadable] [unreadable] [unreadable] [unreadable] [unreadable]